Recruits being measured for uniform, probably in London This is one of a series of photographs commissioned by the Ministry of Information in 1917 to record the various procedures of enlistment.

Recruits of the Lincolnshire Regiment training in England, September Here recruits are learning rifle drill.

Aerial photograph showing the trench system between Loos and Hulluch, July 1917.

German barbed wire defences : a portion of the Hindenburg Line, October 1918.

New Zealand soldier examining his shirt for lice, Western Front 'Chatting', as it was called, became a frequent ritual of trench life and was often done with the help of a candle to burn the eggs laid by the lice along the seams of clothes.

A water cart stuck in the mud at St. Eloi during the Third Battle of Ypres, 11 August Muddy conditions were a major problem on the Western Front and were particularly bad in Flanders. The summer of 1917 was one of the wettest summers on record. Not only did mud create unpleasant conditions for the soldiers to live in but it made transporting supplies extremely hazardous.

Stretcher bearers bringing in the wounded through the mud at Passchendaele. The Battle of Pilckem Ridge, near Boesinghe, 1 August 1917.

Front-line trench showing sentry and sleeping soldiers at Ovillers-la-Boiselle on the Somme, July In this photograph one man crouches on the fire-step while his comrades rest but with weapons at the ready. 'A' Company, 11 Cheshire Regiment.

Men of the 2nd Australian Division in a front-line trench cooking a meal, Croix du Bac, near Armentieres, 18 May A variety of cooking methods was employed including primus stoves and braziers and soldiers produced a kind of hot 'bully beef' hash from tins of corned beef.

British troops receiving dinner rations from field kitchens. Ancre area of the Somme, October Hot food was not supplied to front-line soldiers until late 1915 and even then was by no means a regular occurrence.

Fatigue party carrying duckboards over a support line trench at night, Cambrai 12 January It was general practice to do most fetching and carrying supplies under cover of darkness. Although this could be hazardous in the muddy, uneven conditions of the trenches, it was still safer than risking enemy fire in the daytime.

Canadian troops : sleeping and writing letters, February Night-time in the trenches was often a busy time: wiring parties, fatigue parties and raiding parties would all be sent out at night. The day-time, therefore, was the time for relaxation and trying to catch a little sleep.

French women selling farm produce to British soldiers in the market place at Cassel. Cassel, where Field Marshal Haig had his headquarters, was well behind the line and during rest periods British soldiers could take advantage of the local produce.

Troops embussing in Arras to go back for a rest, May 1917, having taken part in the Battle of Arras. The buses being used are London 'B' type buses, some 1,300 of which were requisitioned by the army in October 1914 as troop carriers on the Western Front. Certain adaptations were made: the lower-deck windows were boarded up, the red paint was replaced by khaki and storage racks and tool kits were added.

Gas sentry ringing an alarm near Fleurbaix, 15 miles south of Ypres, June Gas was first used on the Western Front by the Germans during the Second Battle of Ypres in April Chlorine was the first gas to be employed, followed by phosgene in December of that year. Various warning signals were used in trenches, bells, rattles, empty shell cases among them. The soldier in the photograph is wearing the hypo or tube helmet, which was in use from late 1915 until the end of 1916.

Aerial photographs showing a gas attack at Carnoy-Montauban on the Somme, June Montauban, which was in German hands, can be seen in the top left hand corner and Carnoy, which was behind the British lines, in the bottom right hand corner. The gas is being released by the 18th Division as part of the preparations for the Somme offensive.

Line of men blinded in a tear gas attack during the Battle of Estaires near Bethune, 10 April These men of the 55th (West Lancashire) Division are at an advanced dressing station.

Troops moving forward through barbed wire as part of the Somme offensive of July This photograph is a still from the 1916 film, The Battle of the Somme, an official film made for screening in British cinemas during the war.

British Mark IV tank as it appeared to occupants of the German trenches at Wailly during the Battle of Cambrai, 21 October The tank was first used during the Somme offensive in September 1916 but in such small numbers that its effect was minimal. By the autumn of 1917 many valuable lessons had been learned.

Delville Wood on the Somme after heavy bombardment, September This is typical of the scenes of devastation after a major offensive. It took a very long time for the forests and soil of France and Belgium to recover from the effects of shells and poison gas.

Loading a 15-inch howitzer near the Menin Road, in the Ypres Sector, October This is one of many such large howitzers which pounded the enemy's reserve area and demolished concrete fortifications.

Combined photograph showing Passchendaele before and after bombardment. Passchendaele played a central part in the Third Battle of Ypres in 1917 and became a byword for the horrors of the First World War.

Scene in an advanced dressing station. Dressing stations such as this were situated well behind the front line but were generally very basic. Huts and barns were taken over and simple surgery was carried out. It was important to select a site that would not be too vulnerable to attack.

A German war cemetery containing five thousand graves at Sailly-sur-la-Lys, 12 October 1918.